For assembling watch bezels and crystals, so-called “friction fit” mountings are known, which often require sealing gaskets to absorb the radial compression forces of the crystal on the bezel. These methods are often used for top of the range watches using metal bezels and crystals made of very hard material, such as corundum or sapphire, the cost price of which is very high.
For plastic bezels and crystals, alternative mounting methods to the driving in method are known, which use for example bonding, ultrasound welding, or snap fit—also called clip-fit—mounting of securing elements by elastic deformation during assembly. However, bonding requires laborious implementation for mass production for precise and repeated positioning of the parts to be assembled; and ultrasonic welding requires heavy investment. Finally, snap fit mounting often requires machining complex geometries to ensure efficient holding, and play often quickly appears between the various assembled elements after the creep deformation of the plastic material.
There is therefore a need for a solution that allows a bezel to be secured without any of the aforementioned drawbacks of the prior art, notably proposing a simple assembly method that is easy to implement, with reduced production costs.